Hydraulic control for throttle valves



June 22, 1937. J, H. WYNN 2,084,368

HYDRAULIC CONTROL FOR THROTTLE VALVES Filed OCT.. l2, 1932 Patented June 22, 1937 UNITED STATES HYDRAULIC CONTRQL FOR THROTTLE VALVES James H. Wynn, Gary, Ind., assignor to Bendix Products Corporation, South Bend, Ind., a corporation of Indiana Application October 12, 1932, Serial No. 637,565

5 Claims.

This invention relates to hydraulic remote control for throttle valves, the invention being particularly useful in connection with the internal combustion engines of aeroplanes for securing 5 accurate adjustment and maintenance of said adjustment of the throttle valves for supplying fuel to the engine.

An important object of the invention is to provide an improved hydraulic transmission be- 10 tween a control lever and the throttle valve of a carbureter which will positively and precisely translate the movement of the control lever into adjustment movement of the throttle valve and will accurately maintain such adjustment.

, Another objectof the invention is to provide a hydraulic transmission system Whose operation is entirely independent of valves and in which movement of a controll member in any direction is positively transmitted hydraulically to the 20 carbureter throttle valve for corresponding adjustment thereof.

A further object is to rigidly support directly on the carbureter the elements which respond to the hydraulic uid displacement and to connect such elements directly with the throttle valve shaft so as to eliminate all unnecessary joints or connections.

Another object of the invention is to use light but strong material for the hydraulic elements and to so construct them that they may be readily assembled or disassembled and replaced when worn out.

Still another object is to construct and arrange the hydraulic fluid displacing elements so that they may be easily and accurately moved but will maintain a seal against leakage.

Still a further object is to provide an improved valve structure for readily permitting the connection with the transmission system of' pump means for replenishing or refilling the elements with fluid.

The invention also includes other features of construction, arrangement and operation in addition to those referred to above.,

Referring now to the drawing,

Figure 1 shows more-or less diagrammatically a carbureter in side elevation, and a controlling lever, and the intervening hydraulic transmission structure of which the cylinders and pistons and their supports are shown in vertical section;

Figure 2 is an enlarged diametral sectional view of the valve structure for attachment of the replenishing or refilling apparatus; and

Figure 3 is an end view of the valve structure showing particularly the lockingmeans therefor.

On'the drawing C represents a carbureter having the outlet I thru which extends the shaft I I bearing a throttle valve I2, the carbureter being located close to the engine to be controlled.

A control lever I3 is located at the point from which control of the carbureter is to be effected. In an aeroplane this lever will be in the cockpit.

The hydraulic transmission system between the control lever and the carbureter is shown as comprising a pair of master cylinders M and M and 'a pair of operating cylinders O and O'. 'I'hese cylinders may be all of the'same construction, each being preferably in the form of a tube oi.' strong metal such as steel or steel alloy.

A supporting base or plate I4 is provided for the cylinders M and M and has the annular lugs I5 'and I5' extending therefrom into which the respective cylinders thread at their inner ends, the plate I4 thus forming heads for the cylinders.

` 'Ihe plate I4 may be secured to the instrument panel in the 'cockpit of an aeroplane or to any other convenient support. Extending from the plate I4 midway between the cylinders is the arm I6 having the yoke I1 at its outer end receiving u and preferably formed of some light metal such as.

aluminum.

Each of the guide heads in cylinders M andM' carries a. cross pin)2l, these cross pins forming fulcrum supports for the inner ends of connecting rods 22 and 22' terminating at their outer ends in yokes 23 and 23' which receive the control lever I3 and are pivoted thereto kby pins 24 and the axis of the fulcrum. pin I8 for the lever.

24', the axes of these pins being equidistant from- With this arrangement when the control lever is swung the pistons in the cylinders M and M will be shifted in opposite directions through equalV distances.

'I'he operating cylinders O and O' are rigidly -mounted and supported directly on the carbureter structure. As shown lugs 25 and 25 extend from the carbureter frame and are preferably formed integral therewith and these lugs have the cylindrical pockets 26 into which the cylinders O and O' thread at their lower ends, the 'base walls 21 of the lugs then forming heads for the cylinders. The guide heads I3 in tlfese cylinders have each a. cross pin 28, these pins forming fulcrum supports for the lower ends of connecting rods 29 and 29' which, at their upper ends, are pivoted to a cross lever 30 secured to the throttle valve shaft II. The axes of the cylinders 0 and O are equidistant from the axis of the throttle` valve shaft II so that shift of the piston structure in oneof the cylinders in one direction will be accompanied by shift of the piston structure in the.

through the same distance.

other cylinder in the opposite direction, but

The various connections between the connecting rods and the piston structures and the controlling levers are designed to reduce friction and wear to a minimum and to eliminate any lost motion.

Extending between the cylinders M and O and secured to the heads of the cylinders by suitable connections is a duct 3I, and a similar duct 32 extends between the cylinders M and O', and these ducts may be the ordinary brass or copper tubing well-known in the aviation or automobile vehicle art.

The cylinders and tubes are entirely fllled with a suitable fluid whose co-eificient of expansion under temperature changes is substantially negligible and which will not freege'in any of the temperatures to which it may be subjected while in service. In the arrangement 4shown the control lever I3 is in a vertical or midway position and the throttle valve I2 is in substantially half open position and the piston structures are in intermediate position in their respective cylinders. If the control lever I3 is now shifted or swung in clockwise direction, 'the piston structure within the cylinder M will be shifted inwardly to displace the fluid between the piston cup 20 andthe head I4 and force it to flow through the tube 3| into the cylinder O so that the piston structure in cylinder O is raised and the lever 30 rotated in clockwise direction to cause further opening movement of the' throttle valve I2. At the same ltime the piston structure in cylinder M will be shifted outwardly with the control lever and the piston structure in cylinder O' will be shifted downwardly by the lever 30, the fluid being displaced from the cylinder O' and flows through the duct 32 into the cylinder M. As the distances between the lever fulcrum axis I8 andl the axes of the connecting rod connections 24, 24 with the lever are the same and of the same length as the distances from the axis of the throttle valve shaft II to the connections of the lever 30 with the connecting rods 29 and 29'-, the piston structure in cylinder M' will move outwardly in accordance with the flow of fluid into the cylinder M' from the cylinderO' and the piston structures in these cylinders will therefore be subjected neither to pressure nor to suction.

If the control lever I3 is swung in counter clockwise direction, the fluid will be positively displaced out of the cylinder M' to flow through the duct 32 into the cylinder'O' for positive rotation of the shaft II and adjustment of the throttle valve I2, the fluid then flowing from the cylinder O through duct 3i and into cylinder M as the piston structure in cylinder M moves routwardly` and the piston structure in cylinder l0 moves at the same rate inwardly. I thus provide a perfectly balanced hydraulic transmission by means of which any movement of the control lever is positively transmitted to the carburetor throttle valve and an adjustment once made will lduring reciprocation therein.

'ber will intimately t in the cylinders and will prevent any leakage, the heads I 9 'of light materlal such as aluminum serving merely to support the piston cups and assist in guiding them placements can very readily be made, en-

Repairs or Vretire cylinder structure can be readily unscrewed from its supporting base, and by pulling out any of the pivot pins at the outer ends of the connectingv rods, the corresponding piston structure can be withdrawn from its cylinder. To facilitate filling of the piston with the hydraulic fluid after installation of the piston, or-for refllling at any time, a preferred form of valve structure is provided for the cylinders. This valve struc'-, ture is best shown in Figures 2 and 3 and comprises a cylindrical body 33 having the threaded end 34 for fitting the openings 35 one of which is provided in the head of each of 'the cylinders. The outer end of the body 33 has the bore 33' for receiving the head 36 of a needle valve 3l, the head having threaded connections in the bore so that by turning thereof the needle valve may be shifted axially in the bore. At its inner end the body has the bore 38 of smaller diameter and between the bores is provided the valve seat,

39 for the needle end of the valve. A nipple 40 extends from the body 33 and communicates with the inner end of the valve chamber 33 and this nipple is threaded at vits outer end for attachment to a conductor.

Between the valve head and point the body 33 has the annular internal shoulder 4I between which and the valve head is interposed a rubber gasket or bushing 42 forminga vseal against the escape of fuel past the valve head. In its outer end the valve headr has a number of diametrally extending slots 43 for engagement by a suitable tool such as a screw driver for turning and 4adjustingthe valve, the body at itsouter end inders. For example, the cylinders O and M may first be fllled and to do t is the lead from the pump is connected with he nipple 40 of the valve for the cylinder M and this valve and the valve for the cylinder O are opened, the latter valve being preferably opened only a small distance. As the pump is now operated. fluid will be pumped to flll the cylinders and the duct 3l and any air will be forced out through the nipple of the valve for the cylinder O. A pipe might be connected with the nipple 40 of the `valve of cylinder O and extended into a vessel into which the fluid will flow, and, as soon as there are no longer any air bubbles rising in the vessel, the operator knows that the cylinders and duct are entirely fllled with fluid. The valves are then closed and the pump mechanism is disconnected and applied to .the other cylinders M and O'for filling in the same manner.

I have thus `produced a reliable and efllcient.y

system adapted particularly for remote control of aircraft engine carbureter throttles and which permits of a positive adjustment of engine speeds for purposes of synchronization where the aircraft has more than one engine, the adjustment being with minimum effort, and when once made being maintained under all conditions oi' vibration. torsional weave, variations of temperature, or other conditions which might tend to disturb the adjustment. rI have furthermore provided a system in which yno valves are depended upon for adjustment operation, and a system in which the number of connections has been 'reduced to a75- toI minimum and in which wear is reduced to a minimum.

It should be noted that in the system shown there is a remarkable factor of safety in that,

should a leak or break occur in one side of the system, proper and safe control of the carbureter valve can be accomplished by the other side of the system until repairs can be made. For example, suppose that the line or duct 32 should become leaky or broken, then swing of the control lever I3 in clockwise direction will, as before, shift the piston in master cylinder M to displace the fluid for movement of the piston in v operating cylinderO and corresponding opening movement of the throttle valve, and when the lever is swung in the opposite direction the piston in cylinder M, when pulled outwardly, will cause suction on the fluid in line 3i and downward movement of the piston in cylinder O for closing movement 'of the throttle valve.

I do not desire to be limited to the exact construction, arrangement and operation shown and described as changes and modifications may be made without departing from the scope or spirit of the invention as defined in the appended claims.

I claim as follows: N,

1. In combination, a throttle valve for an internal combustion engine, said valve including a casing, an operating cylinder rigidly mounted on said valve casing and having a pressure responsive structure connected'with said throttle valve for opening said throttle valve, a second operating cylinder rigidly mounted on said valve casing and having a pressure responsive structure connected with said throttle valve. for closing said throttle valve, a pair of master cylinders at a point remote from said valve each having a pressure creating structure, a control lever connected with both of said master cylinder piston structures, conduits connecting each of said masfer cylinders with one of vsaid operating cylinders, said cylinders and conduits being filled with hydraulic fluid, whereby movement of said control lever in either direction and the pressure creating structures connected therewith will be transmitted by said fiuid positively to the pressure responsive structures of said operating cylinders for positively moving said valve in both directions.

2. In combination, a throttle valve having a casing, an operating lever for said valve, a pair of operating cylinders both secured to said casing and each having a piston connected with a separate end of said lever, a pair of master cylinders each having a piston, a pivoted control lcver connected on opposite sides of its pivot with both of the pistons of said master cylinder, and a conduit connecting each of said master cylinders with one of said operating cylinders, said cylinders and conduit being filled with hydraulic fiuid whereby movement of the master cylinder pistons by said control member will be transmitted by said fiuid to the pistons of the operating cylinders and to said operating lever for actuation of said valve.

3. In combination, a throttle valve having a casing and having a shaft, a lever secured to said shaft for rotating said shaft to open and close said valve, a pair of equal dimension fluid motors mounted rigidly on said casing and having their axes respectively offset on opposite sides of the axis of said shaft, pistons in said cylinders,

piston rods pivotally connected to said c/ylinders mension as said fluid motors and both being located at points removed from said uid motors, a support for said master cylinders, an arm extending from said support between said master cylinders, a hand throttle control lever pivoted cn said arm,pistons for said master cylinders, piston rods connected pivotally to each of' said master cylinder pistons and at their opposite ends pivotally connected to said control lever at points on opposite sides of and equally distant from the pivotal connection of said control lever with said arm, and conduits connecting each of said master cylinders respectively with one of said fiuid motors, said cylinders, motors and conduits being filled with hydraulic fluid, whereby movement of said control lever in either direction will be positively transmitted by the hydraulic link to cause a corresponding movement of the valve lever.

4. In combination, a throttle valve having a casing and provided with a valve shaft, a pair of uid motors mounted rigidly on said casing and each having a piston connected with said valve shaft, a pair of master cylinders both located at points removed from said casing, a pivoted control lever, a pair of pistons for said master cylinders each connected with said control lever and arranged to be moved in opposite directions in said master cylinders when said lever is moved about its pivot, conduits connecting said master cylinder with said iiuid motors, said v cylinders, motors and ducts being filled with hydraulic fiuid, whereby fluid displaced by inward movement of one of the pistons in its master cylinder upon operation of said control lever in either direction will cause corresponding movement of one of the pistons in its operating cylinder and corresponding movement of said valve shaft and valve, and controlled inlets and outlets for each of said cylinders arranged to be connected with pump structure for supplying fiuidto said cylinders or to be connected for the outflow of air and superfluous fluid from said cylinders.

5. In combination, a throttle 4valve having a casing and provided with a valve shaft, a pair of iiuid motors mounted rigidly on said casing and each having a piston connected with said valve shaft, la pair of master cylinders both located at points removed from said casing, a pivoted control lever, and a pair of pistons forv der and corresponding movement of said valve shaft and valve.

' JAMES H. WYNN. 

